This summer, the Ice Bucket Challenge took social media by storm. This challenge aimed to raise awareness for amyotrophic lateral sclerosis (ALS) and was a viral sensation.

For two months, countless videos of celebrities, internet stars and everyday cropped up on the web with these people having buckets of ice-cold water poured over their heads.

Actor Samuel L. Jackson is now challenging all of those celebrities who participated in the Ice Bucket Challenge to step up to a new challenge–sing “We Ain’t Gonna Stop Till People Are Free.”

“We Ain’t Gonna Stop Till People Are Free” has become the anthem of a growing nationwide movement against police violence and brutality. Sparked by the failure of grand juries to indict the police officers involved in the recent deaths of Eric Garner (New York) and Michael Brown (Ferguson, Missouri), this movement has sparked protests and rallies in cities across the country. This past weekend, there were marches in both Washington, DC and New York City that were attended by tens of thousands of people in the two cities.

Jackson took to Facebook over the weekend and his post has been viewed by almost two million people and shared almost 60,000 times.

The original song was penned by Luke Nephew from the group Peace Poets. There is a line in the song that references Eric Garner’s last words (“I can’t breathe”) before dying in chokehold placed on him by a member of the New York Police Department.

Nephew has said that these words, along with the protests of the people of Ferguson and New York, are what inspired the song. The recently-released video features real footage from the protests and can be seen here.

Celebrities that have accepted the challenge include Right Said Fred, Dru Hill, MTV’s The Waatcher and a host of other YouTube personalities.